Weakest digital link: DAC - Streamer - Server?

Members here like @jasonbourne52 tell you that the DAC is the most important part of the chain. Then, in their very next breath they tell you that they all sound the same and don't spend over a couple hundred dollars or you are an idiot.

Good times...

Thanks guys, lost of great advice.  To be more specific, I currently OWN a nice NAS (Synology DS920+) which I use for backup, PLUS I stream ALL of our movies/TV shows/Baby stuff from it, so it's for sure capable of streaming audio!

I also just bought an Innuos Zen3, to RIP CDs mostly and the question is, should I keep it? or get rid of it, and just host my files on my NAS... THEN get a good streamer like Auralic/Aurender instead. 

I know CLOCK makes the biggest difference in Digital Audio, and noise coming into the DAC, BUT hosting files shouldn't matter, so while Innuos DIRECTLY connected to my DAC WOULD be better than if my NAS was directly connected to my DAC, IF BOTH are elsewhere (my server closet), WHY would it make a difference?!

Essentially, I wanna simplify, host ALL of my Video/Audio on my NAS, then get a good streamer/DAC to play off it, or play off Tidal when needed and be done. With Innuos I have to maintain TWO separate servers, one for Audio, the other for Video and other files. 

To sum up however because Cindy will be along shortly to tell everyone what's what.

Gotta love it when your reputation proceeds you ....

Let's do a thought experiment:

I make a DAC. The DAC has a SD memory card on which there is music. The DAC of course reads the music from the memory card, puts it in a buffer, and then plays it out. What impact does the SD card have on the quality of music assuming it is not broken? None. I think most would accept that. If someone does not, then an reasoned discussion is impossible.

Now let's say I have a cheap server or expensive server/streamer, and it connects to my DAC. It does it using USB or Ethernet. The DAC just like above, reads the data (perfectly), and puts it in a memory buffer?  How is this at all any different from the above? From the data side none. They both get perfect data.  One one and singular difference is noise. So now we know the difference between a SD Card, a NAS/Computer and an expensive streamer is purely noise.

Ethernet:  This is already electrically isolated. There is a transformer on each end.  That is pretty effective noise isolation. Being Ethernet, you can place your hardware a distance away if you are worried about AC noise, and/or buy one of many AC filters.  If you are still worried, there are Ethernet filters that claim to remove unnecessary frequencies from Ethernet  (keeping in mind you already have two isolation transformers).

USB: Direct electrical connection, hence high potential for ground noise. No worries, a really good USB isolator is about $300, maybe $400 with a linear supply. I hear Topping has one <$100 now. Optical isolation. No direct noise path. You have some distance limitations.

What are you missing? Nothing. You seem to understand the basics just fine.

The oft repeated saying "The chain is only as strong as its weakest link", sounds nice, but wrong. How about looking at it another way. If the chain does not break, then it does not matter if any of the links are stronger of weaker. It is good enough to do the job. But that is still wrong because it is not a mechanical chain, it a processing chain.

NAS = -40db noise, DAC-A = -80db rejection - final result = -120db

High End Server = -60db noise, DAC-B = -50db rejection - final result = -110db

Well what do know, it is not about the weakest link, it is the combination. But frankly it does not matter, you would not hear something -110db or -120db noise with music playing .... the chain is more than good enough.

TEST A: Plug / Unplug Ethernet with the volume at the max of the listening level. Do you hear any change in noise? No, then you don't have an analog noise issue.

TEST B: ... really there is no test B, because the next claim will be "well what about digital noise hurting the clock". Well if the analog noise is so low that you can't detect it or super faint, what are the odds it is impacting the super fast transition of clock signals that are at least 1V?  The noise from the internal circuitry in the DACs digital section is likely orders of magnitude higher than external sources with Ethernet or isolated USB.

Thanks Cindy, so my assumption is CORRECT, having my Audio files HOSTED on my NAS in a separate room and using a good streamer/DAC to play them will yield the EXACT same results as if I had a dedicated Audio server (Innuos, etc...) in the same room - BOTH connected via the same network/ethernet cable!

From what I can gather, the dedicated music servers just make the life easier, and make it dumb proof for folks to host their files (Innuos is super easy), but for anyone with technical background like myself, I can simply put my files on my Synology Audio folder and have exact same results with data redundancy, backup, remote access and ease of use! It's currently hosting 4K videos without a problem.

I guess my next question is, WHICH streamer/DAC, under $2K, would do the job best playing files off my NAS PLUS having Tidal/Spotify Connect?